Apparatus for manufacturing fibers of thermoplastic material



Jan. 4, 1966 M. s. FIRNHABER APPARATUS FOR MANUFACTURING FIBERS OFTHERMOPLASTIC MATERIAL Filed Jan. 18, 1962 United States Patent OfiicePatented Jan. 4, 1966 3,227 536 APPARATUS FOR MANUliACTURING FIBERS F'IHERMGPLASTIC MATERIAL Miles S. Firnhaber, Rte. 3, Pewaukee, Wis. FiledJan. 18, 1962, Ser. No. 167,991 11 Claims. (Cl. 65-14) This inventionrelates to an improved apparatus for manufacturing fibers ofthermoplastic material, and more particularly to a novel fiberizingrotor which can b readily disassembled to permit repair or replacementof its parts, and which rotor is adapted to produce a new form of fiberparticularly well suited for insulation purposes.

In the production of mineral wool and similar insulating materials,molten glass or other thermoplastic material in a molten state isusually deposited on a rapidly spinning rotor and centrifugal forcecauses the same to be thrown therefrom in the form of individualfilaments. These filaments are intercepted and acted upon by high speedjets of steam or the like as they leave the periphery of the rotor andare attenuated thereby into the fine, straight fibers ordinarily used ininsulating materials. Such straight fibers have been utilized in themanufacture of mineral wool and similar products for a long time andhave always been considered the most satisfactory type of fiber for thatpurpose. Applicant has discovered, however, that fibers having a curvedor Wavy configuration adhere together better, have superior mattingproperties, and result in an insulating material of greatereffectiveness.

With the above in mind, one of the two principal objects of the presentinvention is to provide a novel rotor assemblage which produces wavyfibers, in contrast to the straight fibers formed by conventionalfiberizing rotors.

In the production of thermoplastic fibers as hereinabove described it isimportant, of course, that the molten material be maintained at a hightemperature while it is on the rotor, and it is therefore necessary thatthe rotor be adapted to stand up under temperatures which sometimesexceed 2500 F. For this reason most prior fiberizing rotors, or at leastthe head portions thereof, have been constructed of a ceramic orrefractory insulating material. Such ceramic rotors are unsatisfactory,however, for the reason that they tend to dry out and crack in arelatively short time, and must be replaced frequently. More recently,efforts have been made to construct fiberizing rotors entirely of metal,which rotors are much more durable and long-lasting than those formed ofceramic materials, but it has been found that the intense heat tends tocause deterioration of the structural integrity of the metal.

To minimize the problem of overheating and deterioration of the metal,recent metal rotors have included various integral means designed tocool the metal during operation, and in addition, such rotors have beenso constructed that the rotor head and other portions which aresusceptible to wear or deterioration can be detached and replaced on therotor proper, thus eliminating the necessity for discarding andreplacing the entire rotor. Unfortunately, however, the integral coolingmeans on such metal rotors have not proven satisfactory. Moreover, eventhough such rotors have been designed so that portions thereof could bedetached and replaced in the event of damage, the intense heatfrequently fuses said rotor parts together and makes it impossible toseparate and remove the same.

With these considerations in mind, the second principal object of thepresent invention is to provide a novel, allmetal fiberizing rotorhaving improved cooling means thereon, and which rotor is so designedthat while the head portion thereof is detachable, and will not becomefused or frozen to the rotor proper, said rotor head is secured to therotor in such a manner that it cannot be inadvertently separatedtherefrom during operation.

A further object of the present invention is to provide a fiberizingapparatus wherein the temperature and viscosity of the molten materialcan be effectively controlled during the fiberizing operation, therebyinsuring that the fibers produced are of consistent quality.

Further objects of the present invention are to provide a fiberizingapparatus as above described which is relatively simple in design andconstruction and which is efficient and reliable in operation.

A still further object of the present invention is to provide a novelfiberizing apparatus which is especially weil adapted for use in themanufacture of mineral wool and similar insulating products, ashereinabove described, but which fiberiz-ing apparatus can also beadvantageously employed in the manufacture of many diverse fibrousmaterials, including rayon and other synthetics.

With the above and other objects in view, the invention consists of theimproved fiberizing apparatus and all of its parts and combinations asset forth in the claims, and all equivalents thereof.

In the accompanying drawing, illustrating one complete embodiment of thepreferred form of the invention, and wherein the same reference numeralsdesignate the same part-s in all of the views:

FIG. 1 is vertical sectional view of the fiberizing apparatus comprisingthe present invention;

FIG. 2 is a horizontal sectional view through the rotor, taken alongline 22 of FIG. 1; and

FIG. 3 is a fragmentary side elevational view of the annular coolingrim, taken along line 33 of FIG. 2.

Basic structure and operation In the operation of a fiberizing apparatusof the general type illustrated (as is described in detail in mycopending applications Serial No. 801,533 filed March 24, 1959, nowPatent No. 3,048,885, and No. 19,209, filed April 1, 1960, now PatentNo. 3,048,886), a stream of molten glass or other thermoplastic materialin a molten state is delivered from a melting furnace through a tube 16(FIG. 1) and is deposited thereby onto a rapidly spinning rotor, whichis designated generally by the numeral 12 in the drawing. Said rotor isformed of metal and includes a cylindrical base portion 1a: which isrotatably drivably mounted on a shaft 18 connected to a motor or otherprime mover, and mounted on the top of said base is a rotor head 24having a dished material-receiving surface 14.

Surrounding and projecting above the rotor head 24 is a metal rim member26 having a multiplicity of apertures 28 therethrough, and mountedthereabove in surrounding relationship to the delivery tube It is acircular gas chamber 36. Said gas chamber is connected by a conduit 38to a suitable source of combustible gas under pressure, and dependingfrom said gas chamber are a plurality of radiant burners 37 which arepositioned to direct flames 39 against the dished top surface of therotor, to maintain the thermoplastic material thereon at a predeterminedtemperature and viscosity.

As the rotor spins, the molten material is thrown therefrom bycentrifugal force and is caused to pass through the apertures 28 in thesourrounding rim member 26, said rim performing the twofold function ofattenuating the filaments and also preventing any incompletely-formedfibers or slugs from leaving the rotor and finding their way into thefinished product. With respect to said rim, it is an advantageousfeature of the illustrated rotor for the reasons described, but it is byno means critical to the novel concepts and structure comprising thepresent invention, and which will be hereinafter described, and theinvention is not to be limited or confined to a rotor structureincluding such a rim. After the filaments leave the periphery of therotor they are intercepted by high-speed, downwardly-directed jets 42emitted from an annular steam or gas ring 46, said ring being connectedby conduits 41 to a boiler or other source, and having a plurality ofspaced discharge orifices in its bottom surface. Said jets 42 aredesigned to abruptly and violently change the direction of thefilaments, thus attenuating the same still more as they solidify, and todirect said filaments downwardly into a receptacle or containertherebelow.

As mentioned, the illustrated fiberizing rotor is formed entirely ofmetal, in contrasts to the ceramic or combination metal and ceramicrotors formerly used. in this respect, it has been found that an alloyconsisting of chromium, nickel, and cobalt is very satisfactory, butother metals or alloys might be preferred for certain fiberizingoperations and the particular metal employed is not critical to thepresent invention.

New rotor structure As will be seen in -lG. 1, the cylindrical rotorbase 16 characterizing the present invention is provided with anenlarged or flanged upper portion 17 and seated thereon is a fiat,concentric ring or disc 29 of still greater diameter. The centralportion of said disc 20' is open and the periphery of said disc isprovided with oblique blades or fins 22 (FIG. 3) which are designed tofunction as fan blades when the rotor is in operation, as will behereinafter described.

The rotor head 24- in the present improved rotor assemblage is seated onthe disc 29, being smaller than said disc in diameter, and theaforementioned upstanding rim 26 included on the illustrated rotorclosely but separably surrounds said rotor head. As is apparent in FIG.1, both said rotor head 24 and rim 26 are tapered upwardly and inwardly,and surrounding said members is a novel locking ring 30 which isdesigned to detachably secure said members together and to the base 16.

Said locking ring 30 is wedgingly fitted over the tapered rim 26, theopening in said locking ring being slightly smaller in diameter than thediameter of the rim at its lowermost point. The inner, annular surfaceof said locking ring is vertical, in contrast to the inclined adjacentsurface of the rim 26, the purpose of which will be seen, and inassembling the unit said locking ring is pressurably urged downwardly toclampingly retain said rim and rotor head members together. The ring Stthe disc 26, and the flanged upper portion 17 of the rotor base areprovided with circumferentially-spaoed, registering apertures, and tosecure said ring to the rotor base bolts 32 are projected through saidregistering apertures and fastened by nuts 34. Not only does thisprovide a simple means for detachably joining the component parts of therotor, but during the fiberizing operation the intense heat on the metalhead and rim members causes said members to expand and to become evenmore tightly wedged against the locking ring 36, thus eliminating thepossibility of said members inadvertently separating or coming offduring operation. After the rotor has been halted for a short time saidhead and rim members cool off and return to their original size, ofcourse, and may then be readily separated from the rotor merely byremoving the bolts 32 and withdrawing the locking ring 30.

Due to the angled nature of the upstanding rim 26 (or the tapered natureof the rotor head itself in the event the rotor does not include such arim), there is a relatively small area of surface contact between saidrim and the inner surface of the locking ring 313, and the possibilityof fusion between said members is practically non-existent. Similarly,because the inner portion of the disc 26 is open there is relativelylittle surface contact between said disc and the underside of the rotorhead, and little chance of permanent fusion between said members.Moreover, the airspace 21 provided by said disc between the rotor headand base members forms an insulating layer therebetween which preventssaid base from becoming overheated.

As a result of the novel locking ring device characterizing the presentimproved rotor it is possible to quickly and easily remove and replacethose portions of the rotor which are most susceptible to wear ordeterioration, and it is not necessary to discard and replace the entirerotor in the event of damage. Moreover, the unique design of applicantsassemblage minrnizes the possibility of the rotor components becomingfused or stuck together during operation, as frequently happens withthose prior all-metal rotors wherein the component parts are intended tobe separable.

Means for producing curved fibers In addition to the detachable andseparable nature of the rotor assemblage characterizing the presentinvention and hereinabove described, the present invention is also novelin that it is designed to produce fibers having a curly or wavyconfiguration, in contrast to the straight fibers heretofore used inmineral wool and similar insulating products. As mentioned, such wavyfibers have superior matting qualities and have been found to produce amore effective insulating material.

As is illustrated in FIG. 1, a supplemental gas ring or chamber 44formed of a pair of complementary, semicircular sections 45 and 46 ismounted above and in surrounding relationship to the regular gas chamber36, being spaced radially outwardly a short distance therebeyond. Saidsupplemental gas ring 44 is provided with depending burners 49 which arepositioned to discharge gas flames 59 against the molten materialfilaments as said filaments are thrown from the periphery of the rotor,and before said filaments are intercepted by the steam jets .2 ashereinabove described. As shown, said ring sections 45 and 46 includesupply conduits 47 and 48, respectively, and in accordance with thepresent invention each of said sections is supplied with combustiblegases at a different temperature. As a result, the flames 5t) emittedfrom the burners of the section 46 are of a different temperature thanthe flames 50 emitted from the burners of the other ring section 45.

When the thermoplastic fibers are thrown from the rotor by centrifugalforce they naturally continue to travel in a generally circular path ororbit around the rotor top, and it has been found that by providingfiberengaging flames or blasts 50 and 50' of different temperatures onthe opposite sides of the rotor the resulting changes in temperatureencountered by the orbiting filaments causes said filaments to assumethe desired, curly or wavy configuration. Moreover, the degree ofcurvature or deflection of the fibers can be controlled by regulatingthe temperature difference between the burner sections, thus permittingthe production with one rotor of varying fiber configurations.

Summary of operation In the use of the novel fiberizing apparatuscomprising the present invention, a stream of molten glass or similarthermoplastic material in a molten state is delivered from a meltingfurnace through the vertical tube 10 and is deposited thereby onto theupper surface 14 of the rapidly spinning rotor 12. Said molten materialis thrown centrifugally from the rotor in the form of individualfilaments or fibers, and as said fibers leave the rotor periphery theyare engaged alternately by the flames 5t and 5t) emitted from thesupplemental gas chamber sections 45 and 46, said flames being ofpredetermined different temperatures and causing said fibers to assume aunique curved form. Said fibers then continue their outward travel untilthey are intercepted by the steam jets 42 which solidify the same anddirect them down- Wardly into a suitable receptacle.

During the operation of the present rotor the aforementioned fins orblades 22 carried on the outer peripheral edge of the disc memberfunction as fan blades and cause a cooling circulation of air againstthe exterior of the metal rotor, thus helping to prevent overheating anddeterioration of the structural integrity of the metal. In addition, ithas been found that the air turbulence created by said fan blades aroundthe rotor has an efiect upon and improves the character of the fibers.In the event the rotor head 24 or its surrounding rim 26 should becomedamaged or eroded, they can be easily removed and replaced merely byremoving the bolts 32 and locking ring 30, and it is unnecessary todiscard and replace the entire rotor.

As will be readily appreciated from the foregoing detailed description,the present invention provides an improved apparatus for manufacturingfibers for insulating materials or for any other fibrous products. It isto be understood, of course, that variations or modifications in thedevice illustrated and described herein will undoubtedly suggestthemselves to those skilled in the art, and all such variations andmodifications are contemplated as may come within the scope of thefollowing claims.

What I claim is:

1. A fiber-forming apparatus, comprising: a rotor body rotatablydrivably connected to a prime mover, said rotor body having an annularflange adjacent its top surface; a generally cylindrical, metal rotorhead seated on the top surface of said rotor body, said rotor head beingsmaller in diameter than said body top and being tapered upwardly; alocking ring wedgingly surrounding said rotor head, said locking ringhaving an inner diameter slightly less than the diameter of the bottomof said rotor head; bolts projected through registering apertures insaid ring and body flange members to releasably secure said locking ringand rotor head to said rotor body; heat-emitting means mounted above andsurrounding said rotor head, said heat-emitting means being positionedto discharge heat against molten material filaments thrown from saidrotor head; and means for regulating the heat discharged by saidheat-emitting means whereby greater heat is discharged around oneportion of the rotor head than around another portion of said rotorhead.

2. A fiber-forming apparatus, comprising: a rotor body rotatablydrivably connected to a prime mover, said rotor body having an annularflange adjacent its top surface; a disc seated on the top surface ofsaid rotor body, said disc being of a larger diameter than said rotorbody; a plurality of fan blades carried by and spaced around theperiphery of said disc; a generally cylindrical, metal rotor head seatedon said disc, said rotor head being smaller in diameter than said discand being tapered upwardly; a locking ring wedgingly surrounding saidrotor head, said locking ring having an inner diameter slightly lessthan the diameter of the bottom of said rotor head; bolts projectedthrough registering apertures in said ring, disc, and body flangemembers to releasably secure said locking ring and rotor head to saidrotor body; a gas chamber mounted above and surrounding said rotor head,said gas chamber being formed of a plurality of sections; a plurality ofburners depending from said gas chamber sections and positioned todischarge heat against molten material filaments thrown from said rotorhead; and means for regulating the heat discharged by the burners ofeach of said gas chamber sections whereby the burners of each sectionemit heat of a different temperature.

3. A fiber-forming apparatus, comprising: a rotor body rotatablydrivably connected to a prime mover, said rotor body having an annularflange adjacent its top surface; a disc seated on the top surface ofsaid rotor body, said disc having an open central portion and being of alarger diameter than said rotor body; a plurality of fan blades carriedby and spaced around the periphery of said disc; a generallycylindrical, metal rotor head seated on said disc, said rotor head beingsmaller in diameter than said disc and being tapered upwardly; a lockingring Wedgingly surrounding said rotor head, said locking ring having avertical inner edge surface and having an inner diameter slightly lessthan the diameter of the bottom of said rotor head; bolts projectedthrough registering aper tures in said ring, disc, and body flangemembers to re leasably secure said locking ring and rotor head to saidrotor body; a jet ring mounted above and surrounding said rotor head,said jet ring being substantially larger in diameter than said rotorhead; a circular gas chamber mounted above said rotor head, said gaschamber being formed of a pair of semi-circular sections; a plurality ofburners depending from said gas chamber sections and positioned todischarge heat against molten material filaments thrown from said rotorhead; and means for regulating the heat discharged by the burners ofeach of said gas chamber sections whereby the burners around one half ofthe rotor head emit more heat than the burners around the other half ofsaid rotor head.

4. A fiber-forming apparatus, comprising: a rotor body rotatablydrivably connected to a prime mover, said rotor body having an annularflange adjacent its top surface; a disc seated on the top surface ofsaid rotor body, said disc having an open central portion and being of alarger diameter than said rotor body; a plurality of angled fan bladescarried by and spaced around the periphery of said disc; a generallycylindrical, metal rotor head seated on said disc, said rotor head beingsmaller in diameter than said disc and being tapered upwardly; asimilarly tapered, apertured metal rim separably mounted on andprojecting above said rotor head; a locking ring Wedgingly surroundingsaid rotor head and rim members, said locking ring having a verticalinner edge surface and having an inner diameter slightly less than thediameter of the bottom of said rim; bolts projected through registeringapertures in said ring, disc, and body flange members to releasablysecure said locking ring, rim, and rotor head members to said rotorbody; burner means mounted above said rotor head and positioned todirect heat against the top surface thereof; a jet ring mounted aboveand surrounding said rotor head, said jet ring being substantiallylarger than said rotor head in diameter; a circular gas chamber mountedabove said rotor head, said gas chamber being formed of a pair ofsemi-circular sections; a plurality of burners depending from said gaschamber sections and positioned to discharge heat against moltenmaterial filaments thrown from said rotor head; and means for regulatingthe heat discharged by the burners of each of said gas chamber sectionswhereby the burners around one half of the rotor head emit more heatthan the burners around the other half of said rotor head.

5. A fiber-forming apparatus, comprising: a rotor body rotatablydrivably connected to a prime mover, said rotor body having an annularflange adjacent its top surface; a plurality of fan blades carried byand spaced around the periphery of said rotor body; a generallycylindrical, metal rotor head seated on the top surface of said rotorbody, said rotor head being smaller in diameter than said rotor bodyflange and being tapered upwardly; a locking ring wedgingly surroundingsaid rotor head, said locking ring having an inner diameter slightlyless than the diameter of the bottom of said rotor head; and boltsprojected through registering apertures in said ring and body flangemembers to releasably secure said locking ring and rotor head to saidrotor body.

6. A fiber-forming apparatus, comprising: a rotor body rotatablydrivably connected to a prime mover, aid rotor body having an annularflange adjacent its top surface; a disc seated on the top surface ofsaid rotor body, said disc having an open central portion and being of alarger diameter than said rotor body; a plurality of fan blades carriedby and spaced around the periphery of said disc; a generallycylindrical, metal rotor head seated on said disc, said rotor head beingsmaller in diameter than said disc and being tapered upwardly; a lockingring Wedgingly surrounding said rotor head, said locking ring having avertical inner edge surface and having an inner diameter slightly lessthan the diameter of the bottom of said rotor head; and bolts projectedthrough registering apertures in said ring, disc, and body flangemembers to releasably secure said locking ring and rotor head to saidrotor body.

7. A fiber-forming apparatus, comprising: a rotor body rotatablydrivably connected to a prime mover, said rotor body having an annularflange adjacent its top surface; a disc seated on the top surface ofsaid rotor body, said disc having an open central portion and being of alarger diameter than said rotor body; a plurality of angled fan bladescarried by and spaced around the periphery of said disc; a generallycylindrical, metal rotor head seated on said disc, said rotor head beingsmaller in diameter than said disc and being tapered upwardly; asimilarly tapered, apertured metal rim separably mounted on andprojecting above said rotor head; a locking ring wedgingly surroundingsaid rotor head and rim members, said locking ring having a verticalinner edge surface and having an inner diameter sli htly less than thediameter of the bottom of said rim; and bolts projected throughregistering apertures in said ring, disc, and body flange members toreleasably secure said locking ring, rim, and rotor head members to saidrotor body.

8. A fiber-forming apparatus comprising a rotatably mounted rotor bodyhaving a top surface with an annular flange, a spacer ring seated onsaid fiange, a rotor head seated on said ring and having a bottom, therebeing a cooling air chamber between the top surface of the rotor bodyand the bottom of said head and within said ring, a retaining ringseated on said spacer ring and surrounding the lower portion of saidrotor head, and means extending through said retaining ring, spacer ringand flange releasably securing the parts in assembled position.

9. A rotor for use in a fiberizing apparatus comprising a rotatablymounted rotor body having a periphery, a spacer ring which is generallyconcentric with said rotor body positioned thereon and having itsperiphery extending along and adjacent the periphery of said rotor body,

8 a rotor head seated on said spacer ring, there being a cooling airchamber between said head and rotor body, fan blades carried by theperiphery of said ring and projecting beyond the rotor body, and meanssecuring the spacer ring and rotor head in assembled relationship onsaid rotor body.

10. A rotor for use in a fiberizing apparatus comprising a rotatablymounted rotor body having a periphery, a spacer ring which is generallyconcentric with said rotor body positioned thereon and having itsperiphery extend ing along and adjacent the periphery of said rotorbody, a rotor head seated on said spacer ring, there being a cooling airchamber between said head and rotor body, fan blades carried by theperiphery of said ring and projecting beyond the rotor body, and meansremovably securing the spacer ring and rotor head in assembledrelationship on said rotor body.

11. A fiber-forming apparatus comprising a rotatably mounted rotor bodyhaving a top surface with an annular flange, a spacer ring seated onsaid flame, a generally cylindrical rotor head seated on said ring andhaving a bottom and an upwardly tapered periphery, there being an airchamber between the top surface of said rotor body and the bottom ofsaid head and within said ring, an apertured rim surrounding said rotorhead and projecting thereabove, and means including a retaining ringseated on said spacer ring and surrounding the lower portion of said rimfor releasably securing the parts together.

References Cited by the Examiner UNITED STATES PATENTS 2,603,833 7/1952Stalego et al. 18-26 X 2,609,566 9/1952 Slayter et al. 18-26 X 2,814,82812/1957 Svende -14 2,949,632 8/1960 Kleist et al. 65-14 2,994,918 8/1961Landers. 3,013,299 12/1961 Owens 18-473 X 3,048,885 8/1962 Firnhaber65-15 3,048,886 8/1962 Firnhaber et al. 65-15 3,058,322 10/1962 Erard65-14 FOREIGN PATENTS 147,032 6/1952 Australia.

DONALL H. SYLVESTER, Primary Examiner.

MICHAEL V. BRINDISI, Examiner.

1. A FIBER-FORMING APPARATUS, COMPRISING: A ROTOR BODY ROTATABLYDRIVABLY CONNECTED TO A PRIME MOVER, SAID ROTOR BODY HAVING AN ANNULARFLANGE ADJACENT ITS TOP SURFACE; A GENERALLY CYLINDRICAL, METAL ROTORHEAD SEATED ON THE TOP SURFACE OF SAID ROTOR BODY, SAID ROTOR HEAD BEINGSMALLER IN DIAMETER THAN SAID BODY TOP AND BEING TAPERED UPWARDLY; ALOCKING RING WEDGINGLY SURROUNDING SAID ROTOR HEAD, SAID LOCKING RINGHAVING AN INNER DIAMETER SLIGHTLY LESS THAN THE DIAMETER OF THE BOTTOMOF SAID ROTOR HEAD; BOLTS PROJECTED THROUGH REGISTERING APERTURES INSAID RING AND BODY FLANGE MEMBERS TO RELEASABLY SECURE SAID LOCKING RINGAND ROTOR HEAD TO SAID ROTOR BODY; HEAD-EMITTING MEANS MOUNTED ABOVE ANDSURROUNDING SAID ROTOR HEAD, SAID HEAT-EMITTING MEANS BEING POSITIONEDTO DISCHARGE HEAT AGAINST MOLTEN MATERIAL FILAMENTS THROWN FROM SAIDROTOR HEAD; AND MEANS FOR REGULATING THE HEAT DISCHARGED BY SAIDHEAT-EMITTING MEANS WHEREBY GREATER HEAD IS DISCHARGED AROUND ONEPORTION OF THE ROTOR HEAD THAN AROUND ANOTHER PORTION OF SAID ROTORHEAD.
 10. A ROTOR FOR USE IN A FIBERIZING APPARATUS COMPRISING AROTATABLY MOUNTED ROTOR BODY HAVING A PERIPHERY, A SPACER RING WHICH ISGENERALLY CONCENTRIC WITH SAID ROTOR BODY POSITIONED THEREON AND HAVINGITS PERIPHERY EXTENDING ALONG AND ADJACENT THE PERIPHERY OF SAID ROTORBODY, A ROTOR HEAD SEATED ON SAID SPACER RING, THERE BEING A COOLING AIRCHAMBER BETWEEN SAID HEAD AND ROTOR BODY, FAN BLADES CARRIED BY THEPERIPHERY OF SAID RING AND PROJECTING BEYOND THE ROTOR BODY, AND MEANSREMOVABLY SECURING THE SPACER RING AND ROTOR HEAD IN ASSEMBLEDRELATIONSHIP ON SAID ROTOR BODY.